Increase diameter of hub motor: Larger tires/drill spokes??

[matt912836]

I have this hub motor thats been lying around for the simple fact it is a 10 inch diameter motor which is pretty small and only fits on an electric scooter. I wanted to attempt to put it on a bicycle frame but it being so small is hard to put it on a frame with pedals and not have clearance problems with the floor.


The diameter of the hub from rim to rim is 10 inches. It uses 14 inch bicycle tires which are almost impossible to find in anything other than kids bike tires/tubes, nothing heavy duty like I need for the scooter in the first palce. Theres only two possible things I can do to increase the diameter of the tire:

1. Buy the biggest possible 10 inch moped tire that'll fit on here (and the rim being less than 2 inches wide really limits that to the smallest moped tire)

OR

2. Would it be possible to drill holes around the edge of the rim where the rim grabs on to the tire for spokes? Then attempt to lace it up in a 20" BMX rim

Is number 2 even possible? It would seem to be as simple as drilling the right number of holes, with the right size drill bit for the spokes to be used, in the right alignment, then lacing it properly with the right size spokes. Is it do-able or worth it? Thoughts?

I wanted to throw it on a BMX with one single battery for a fast light ride. The hub motor is definitely a fast turn hub becasue even though its the smallest one I own it has the highest top speed. If I did lace it to a 20" that means the top speed would be even higher. Another option I have would be change the cranks to the ones that were on the scooter (shorter so they allow some pedal clearance), but the BMX bottom bracket does not support square taper cranks, so that would be another problem. If worse comes to worse I'll simply throw a moped tire on it and put it back on the scooter it came from. Only reason I haven't yet is because the original tire that came with it is prone to pinch flats when going over bumps at speed, even with the scooter being full suspension. The 14 inch bicycle tire simply wasnt made to take abuse like I throw at it.

 

[amberwolf]

#2 is possible, as long as the rim edge is strong enough to be a spoke flange. I'd guess that is likely true, but you won't know till you try it.


There is at least one other option:

Make two rings of metal for the spoke flanges, of an inner circumference to use the cover bolts to secure it to the motor, and outer circumference to let the spoke heads clear the outer edge of teh rim.


A fourth option might be to see if the magnet ring is of the very common size used on typical "500w" or "1000w" hubmotors, with the same number of magnets. Then you could take the magnet ring/spoke flange off of one of those with a fried stator and swap them.


Beyond that, it could also be used as a middrive, though that is more complicated.



Also note that if it has a higher top speed, then at the same current/voltage from the controller/battery, it also then has a lower torque. (or takes more current to make the same torque).

 

[gogo]

Just throwing out ideas: It would be great for a one-wheel powered trailer.

 

[spdas]

Aloha, I am using the same 14' motor and you are right bicycle tires wear out very fast. (about 2 weeks max).
The 10-3.00 moped tire is actually a tad small and you might have trouble fitting it

I found a good "scooter" tire in China that has lasted over a month and a half and still is over 1/2 thread (even with my abuse) . Here is the ebay link. (I am using the 14x2.5 now but have the 14x3.0 to replace when it wears out.)

http://www.ebay.com/itm/14-2-50-Tire-Cover-Wheels-Tyre-Electric-Unicycle-Scooter-Electric-Bicycle-/162083546075?hash=item25bceea3db:g:9HsAAOSwAYtWMHJF


(email the guy and he will get you a 14x3.0)

******OR******
lmk if you want to sell the motor


francis